So I'm writing a new adventure for Fighting Fantazine and I was wondering if I should give all the stats for my NPCs with all their spells and details of all new items, spells and rituals, like I have done in the past ones, or do directors just like having the bare minimum stats and coming up with characteristics of NPCs during the game to suit their party (e.g. making a soldier ally stronger because most of the PCs are noncombat types).

Personally, I like quite a minimalist adventure, but with a long background section where I can understand all the story and its plot implications, so that if I need to improvise something unexpected, I have ground basis and solid information.
For example, if I know that the adventure is in dark natural caverns, I don't need to have every time the indication that we are in dark natural caverns. Once is enough until we have a change.

WRT NPCs, I prefer having the m mostly fleshed out (with indications to make them stronger or weaker if it suits your team better), although I don't need a kilometer of common Special skills or common objects that aren't really relevant for the adventure.

I think in my ideal adventure there would be detail on the background and motivations of the NPCs (protagonists and antagonists), a map and layouts of the principal locations, and and some discussion about what the heroes have to do and contingencies which may arise depending on their actions. A decent adventure can be done in just a few pages. Stats etc can be given very concisely.

Bare minimum is also fine, like Traveller amber zone encounters, but some details are always appreciated!

After reading the Northern Invasion (a good read, by the way!!), I suggest minimum stats for the NPCs. I'm not too concerned about their special skills. Gulran the Farmer from that adventure, for example, has a base SKILL and STAMINA of 5. I get that he's not a warrior, but the description tells me everything I need to know about him: "Gulran is very persistent in protecting his farm from the horde, despite the fact that he has no chance." The Talents are a bonus: "Survivor, Robust, Pack horse". I have a picture in my mind of this stubborn old coot that won't give up the land, chasing down isolated goblin scouts with his dogs and mounting their heads on his fence posts, and generally useful in all things farming related. His low skill and stamina tells me he's not a warrior, his trade and description tells me what he is good at.

After reading the Northern Invasion (a good read, by the way!!), I suggest minimum stats for the NPCs. I'm not too concerned about their special skills. Gulran the Farmer from that adventure, for example, has a base SKILL and STAMINA of 5. I get that he's not a warrior, but the description tells me everything I need to know about him: "Gulran is very persistent in protecting his farm from the horde, despite the fact that he has no chance." The Talents are a bonus: "Survivor, Robust, Pack horse". I have a picture in my mind of this stubborn old coot that won't give up the land, chasing down isolated goblin scouts with his dogs and mounting their heads on his fence posts, and generally useful in all things farming related. His low skill and stamina tells me he's not a warrior, his trade and description tells me what he is good at.

I like your adventures.

MORE STATS AND STUFF I AM SUCH A BIG FAN STUART I READ YOUR BLOG!

He just sits there tapping away all day on a tiny screen. But he tells everyone that he is slaying Orcs.

After reading the Northern Invasion (a good read, by the way!!), I suggest minimum stats for the NPCs. I'm not too concerned about their special skills. Gulran the Farmer from that adventure, for example, has a base SKILL and STAMINA of 5. I get that he's not a warrior, but the description tells me everything I need to know about him: "Gulran is very persistent in protecting his farm from the horde, despite the fact that he has no chance." The Talents are a bonus: "Survivor, Robust, Pack horse". I have a picture in my mind of this stubborn old coot that won't give up the land, chasing down isolated goblin scouts with his dogs and mounting their heads on his fence posts, and generally useful in all things farming related. His low skill and stamina tells me he's not a warrior, his trade and description tells me what he is good at.